Wax is used in a variety of industrial applications. Often, the wax is used in a particle form. As such, the production of wax particles can provide an important aspect of such industrial applications that use wax. It can be favorable in many instances for the wax particles to have mono-dispersity or a common particle size. Wax particles are often produced by extrusion of molten wax through an orifice.
Some wax particle formation techniques include extruding molten wax as a jet of wax particles into air or another (static or moving) fluid. The jet of a wax stream is subject to an instability, which ruptures the stream of wax into small molten wax droplets that solidify into the wax particles. The rupturing can be accomplished by a variety of mechanisms, such as by gravity, electrostatics, shear, or the like. Polydispersity of droplets is an inherent feature of instability-driven jet rupture, and has been well studied for over a hundred years. Such a jet-based approach to forming wax particles is shown in FIG. 1A.
Other wax particle formation techniques include extruding molten wax from an orifice into a liquid that forms drops once the wax stream emits from the orifice. The wax stream is extruded into a bath of liquid, and, depending on the relative density between the two fluids, is directed either downward or upward. The drop, upon reaching a critical size, is detached from the orifice via buoyancy, which acts against gravity and surface tension. In most typical cases, drop size is nearly independent of orifice size below a certain threshold (˜2 mm), and it is extremely difficult to produce sub-millimeter wax particles. This is in addition to the fact that the throughput of this method is relatively lower than the jet-based method. Such a drops-based approach to forming wax particles is shown in FIG. 1B.